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Full text of "John_Deere_Riding_Mower_70"

SLIDE TEXT 
ST 70 



CONSUMER PRODUCTS 



70 



LAWN TRACTOR 




Litho in U.S.A. 



SECTION 10 
GENERAL 1 



70 LAWN TRACTOR 



^ 



INTRODUCTION 



In 1966 the 60 Lawn Tractor was intro- 
duced to the Consumer Products Line. 
The 60 Tractor sales have grown stead- 
ily through the 1969 model production. 

Responding to the market demand, the 
60 Tractor has been redesigned for 
19 70 and is now identified as the 70 
Lawn Tractor. 

Increased horsepower, improved opera- 
tor comfort with the isolated engine 
mounting, and new steering gear are 
only a few of the quality features of 
the 70 Lawn Tractor. 



70 GEN 1 






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This is a service program for the 70 
Lawn Tractor, however, most of the 
trouble shooting, removal and replace- 
ment procedures and adjustments apply 
to the 60 Lawn Tractor as well. 

This booklet has many uses. It should 
be maintained in your Service Depart- 
ment library as a ready reference as 
the need arises. 



SPECIFICATIONS: 









WHEEL TREAD 

Front 23-7/16 in. 

Rear 22-1/2 in. 

TIRE SIZES 

Front 13x5.00-6 

Rear 18x8.50-8 

TIRE INFLATION 

Front (with rotary mower) 12 psi 

(with snow thrower or front 

blade) 20 psi 

Rear 6 psi 

DIMENSIONS 

Wheel Base 42-1/2 in. 

Over-all length 59 in. 

Over-all height 37 in. 

Over-all width 30-3/4 in. 

Turns outside 17 in. radius 



BARE WEIGHT (tractor only). 



384 lbs. 



- 1 - 



EQUIPMENT 

34 Rotary Mower 34 Inch Cut 

32 Snow Thrower 32 Inch Cut 

40 Front Blade 40 Inch Cut 

The equipment and accessories for the 
60 and 70 Tractors are interchangeable, 



SECTION 10 
GENERAL 2 



********************* 



PREDELIVERY : 

The 70 Tractor will be shipped as you 
see it here. 

Install the steering wheel and tighten 
it to 10-12 Ft. Lbs. 

Be sure to remove battery before fill- 
ing with electrolyte to prevent damage. 
Always use caution when using battery 
acid as it can be harmful to person and 
tractor. Acid is available from Parts 
Depot in various quantities. 



70 GEN 2 




Be sure to connect solenoid cable to 
positive battery terminal first and 
cover with boot. Connect ground cable 
to negative terminal. Reversing these 
connections may burn out fuse on recti- 
fier panel or possibly damage other 
electrical components. 

To prevent corrosion, coat battery posts 
and cable clamps with petroleum jelly. 
Be sure rubber boot covers positive 
battery terminal. 



********************* 



70 GEN 3 



The rectifier wire is disconnected for 
shipment. This protects the rectifiers 
and fuse from burning out if the trac- 
tor is started manually before the bat- 
tery is installed. After charging and 
installing battery, connect rectifier 
wires at connector "A" on rectifier 
panel. Be sure connectors are pushed 
together firmly. 

More information will be included in 
the Electrical Section. 




_2- 



Be sure to check oil level in the en- 
gine and transmission. Always refer 
to the Predelivery Instructions in the 
Operator's Manual when servicing trac- 
tor or equipment for delivery. 



********************* 



SECTION 10 
GENERAL 3 






CUSTOMER DELIVERY: 

Advise customer to change tractor crank- 
case oil after first two hours of opera- 
tion. This is important as it will re- 
move any abrasive particles, which may 
appear in the first few hours of opera- 
tion. 

Instruct customer in safe operation of 
tractor and attachments. The Impor- 
tance of safety can never be over- 
stressed. 

Explain recommended daily and periodic 
service. 



70 GEN 







********************* 



70 GEN 5 



A super man not exactly, but a 

super dealer maybe! 

Explain the operating instructions and 
adjustments as covered in the Opera- 
tor's Manual. Many customers never 
take the time to read their Operator's 
Manual. The time you spend will help 
make a happy customer, reduce the num- 
ber of service problems resulting from 
customer errors and save everyone in- 
volved time and money. 

Be sure customer has his Operator's 
Manual. 




********************* 



-3- 



SECTION 20 
ENGINE 1 



ENGINE SPECIFICATIONS: 

Manufacturer Tecumseh 

Model VH70 Heavy-duty 

Cylinder Single, cast-iron 

Bore and Stroke 2.75x2.53 in. 

Displacement 15.0 in. 

Type 4-cycle, vertical crankshaft 

Speeds (fast) 1800-3600 rpm 

Speeds (idle) 1200-1700 rpm 

Horsepower 7 HP @ 3600 rpm 

Valve Clearance (intake) cold 0.010 in. 
Valve Clearance (exhaust) cold 0.010 in. 
Compression Release. Internal mechnical 

type 
Crankcase Capacity.... 1-1/2 U.S. Pints 
Type of Crankcase 

Lubricant AM 30730 Summer 

AM 30710 Winter 

We cannot over-stress the importance 
of a clean air filter. Tap filter 
lightly to remove dirt. Never use 
compressed air or a liquid cleaner of 
any type to clean filter as these may 
damage air filter and result in damage 
to the engine. Replace filter every 
100 hours of service or sooner if it 
becomes extremely dirty. 

Shown is a vibrating tachometer avail- 
able from Tecumseh (part no. 670156, 
price $3.95) which will enable you to 
set the engine speed accurately. 



70 ENG 1 










********************* 



70 ENG 2 



The serial number plate for the engine 
contains several groups of numbers. 
The serial number of the engine is the 
number which immediately follows the 
word serial on the serial plate. This 
number is valuable to the factory and 
should appear on warranty claims and cor- 
respondance referring to engine pro- 
b lems . 



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-4- 



SECTION 20 
ENGINE 2 






SERVICE TOOLS: 

Shown are the service tools required 
for the VH 70 Engine. They are from 
left to right; 

1. Flywheel Knock-off Nut. 

(Tecumseh 670169) 

2. Oil Seal Driver Adapter. 

(Tecumseh 28677A) 

3. Seal Seat Tools. 

(Tecumseh 2 86 7 7 A) 

4. Bearing Tool. 

(Tecumseh 28678) 

5. Oil Sleeve Tool. 

(Tecumseh 28676) 

6. Flywheel Puller. 

(OTC 9 15 A) 

************* 



70 ENG 3 




******* 



70 ENG 4 



Torque cylinder head bolts to 140-200 
in. lbs. in the sequence shown to assure 
uniform seating of the head and head gas- 
ket. For other torque values refer to 
SM 2091, 2-7 HP Tecumseh Engine Service 
Manual. These are available through the 
normal JOHN DEERE Service Manual channels. 




******************* 



CLEANING SHROUDS AND FINS: 

It is important to keep the shrouding 
and fins free of grass and debris to 
maintain proper cooling of the engine. 
Shown here is the easy method of re- 
moving the shrouding for cleaning. 
Use compressed air to clean hard to 
get at areas. 

Remove top bolt on each side of cowl 
assembly, loosen lower bolts and tilt 
grille and hood assembly forward. 

Remove upper three head bolts. 

Remove screws holding shrouds - one 
at dipstick tube - one at battery 
ground strap connection. Debris in 
the fins can cause hot spots and pre- 

ignition. 

********* 



70 ENG 5 




************ 
-5 - 



SECTION 20 
ENGINE 3 



ENGINE REMOVAL: 

If the engine is to be removed for ma- 
jor service, use the following sequence. 

NOTE: Grinding valves, head and head 
gasket service and many other minor re- 
pairs do not require removal of the en- 
gine. 

Drain oil from crankcase. 

Close fuel shut-off and disconnect fuel 
line at shut-off. 

Remove (4) bolts holding grille and 
hood assembly to frame. 

Remove the solenoid cable at starter 
terminal and both wiring harness leads 
at rectifier panel. 




********************* 



70 ENG 7 



Remove throttle cable at carburetor. 
Remove ground wire at engine. 




********************* 



70 ENG 8 



Remove clutch arm, PTO brake, clutch 
cone. Push upon idler and remove 
drive belt from the rear sheave first. 
Remove (4) bolts in engine base and 
lift engine from tractor. 

Note the correct belt twist. The bot- 
tom strand runs from rear sheave to 
the left hand side of the front sheave. 
Reversed twist will result in reversed 
travel and may cause transaxle damage. 




********************* 



-6 - 



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SECTION 20 
ENGINE 4 



RUBBER ENGINE MOUNTS: 

The engine in the 70 Tractor is iso- 
lated from the chasis on three rubber 
mounts. To replace the rear mount the 
engine must be removed. 



70 ENG 9 




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70 ENG 10 



The front mounts may be replaced with- 
out removing the engine. 

To install engine back in tractor, re- 
verse the removal procedures. 




AAA****************** 



^ 



THROTTLE CABLE INSTALLATION: 

Place the control lever in the high- 
speed position. ' 

Be sure that the control cover screws, 
the screws in the slotted holes on the 
left side of the control cover plate, 
are loose. 

Align the carburetor control lever as 
shown so that the hole in the crook of 
the control lever is in alignment with 
the slot in the carburetor control cov- 
er. This is the high-speed position. 
Any movement of the control lever to the 
right begins to close the choke. 

Place a 3/32" alignment pin through 
control cover slot, choke lever, and 
choke operating arm. 



70 ENG 11 




7 - 



SECTION 20 
ENGINE 5 



This will align the control cover with 
the choke operating lever and choke 
lever itself. Tighten the cover screws. 
Then, install control cable in carbure- 
tor control lever. Tighten clamp on 
control cable and remove alignment pin. 

The alignment pin used was cut from a 
standard wire coat hanger. 






********************* 



REINSTALL PTO CLUTCH: 

Adjust PTO brake assembly for 1/16" 
clearance when PTO is engaged. Com- 
plete adjustment is shown in Section 
70 of this program. 



70 ENG 12 




********************* 



OVERHAUL PROCEDURES: 

Refer to SM 2091, 2-7 HP Tecumseh En- 
gine Service Manual for details for ser- 
vicing the engine. 

The safe service man relies on a library 
as well as his memory to prevent the 
latter from becoming disengaged while 
performing service work. 



70 ENG 13 




******************* 






SECTION 20 
ENGINE 6 






^ 









ELECTRIC STARTER INOPERATIVE OR 
WILL NOT TURN ENGINE 

A. Clutch-brake pedal is not fully 
depressed. 

1. Depress clutch-brake pedal. 

B. PTO clutch lever is engaged. 

1. Pull clutch lever to rear (dis- 
engaged position) . 

C. Solenoid clicks but engine will not 
start. 

1. Check for discharged battery. 

D. Engine still will not start. 

1. Check electrical connections. 

2. Check for faulty clutch-brake 
and PTO safety start switches. 

HARD STARTING 

A. Faulty Ignition. 

Check for spark by removing the 
spark plug and grounding the plug 
to the cylinder head. Crank the 
engine with the starter and observe 
the spark. If no spark, check: 

1. Spark plug gap is incorrect. 

2. Spark plug electrodes are pit- 
ted or fouled. Replace plug. 

3. Breaker point gap is incorrect 
or breaker points are worn or 
pitted. 

4. Faulty magneto. 

B. Faulty Carburetion. 

1. Gasoline may not be getting to 
the carburetor because fuel line 
or strainer may be gummed and 
plugged. Clean strainer and 
fuel line. 

2. Carburetor may be dirty or out 
of adjustment. 



ENGINE TROUBLE SHOOTING 

ENGINE MISSING UNDER LOAD 



A. Check spark plug for proper gap - 
.030 

B. Check for lean fuel mixture. Adjust 
carburetor high speed screw. See 
Fuel Section. 

C. Check for dirty (fouled) spark plug 
or improper type plug. 

D. Pitted or worn breaker points should 
be replaced with a new set. 

BACKFIRING 

A. Check carburetor for lean fuel mix- 
ture. See Fuel Section. 

B. Sticky intake valve or improper 
ignition. 

KNOCKING 

A. Use only a quality grade of regular 
gasoline. 

B. Check engine for overheating. 

C. Check crankcase oil level. Fill to 
"FULL" mark on dipstick. 

D. Check carburetor for lean fuel mix- 
ture. See Fuel Section. 

E. Possible loose connecting rod, im- 
proper timing or excessive carbon 
in combustion chamber. 



9 - 



SECTION 20 
ENGINE 7 



ENGINE TROUBLE SHOOTING CONT. 






LOSS OF ENGINE POWER 

A. Overheating. 

1. Check and clean intake screen 
and engine shrouds. 

2. Check for use of premium gaso- 
line with high octane rating. 
Use regular gas only. 

3. Check carburetor for lean fuel 
mixture. 

4. Check oil dipstick for excessive 
or too little oil in engine 
crankcase. Maintain oil level 
at "FULL" mark on dipstick. 

5. Check breaker points for proper 
gap. 

6. Remove excessive load on tractor. 

B. Dirty Air Filter. 

1. Check and clean air filter. 

C. Choke is Partly Closed When Opera- 
ing at Full Throttle. 

1. Make sure throttle choke control 
cable is properly adjusted. 

ENGINE OPERATING ERRATICALLY 

Check the following: 

A. Carburetor setting. 

B. Clogged fuel line. 

C. Water in fuel. Drain fuel and clean 
fuel line. 

D. Faulty choke control. 

E. Loose spark plug wire. 

F. Air leaks in carburetor connections 
or gasket. 

G. Carburetor jet clogged. 
H. Loose throttle cable. 

I. Fuel tank vent hole plugged. 



ENGINE WILL NOT IDLE 

A. Check carburetor adjustments. See 
Fuel Section. 

B. Dirty carburetor. 

C. Check and set spark plug gap - .030, 

D. Check carburetor for air leaks in 
gasket. 

E. Possible leaky valves or faulty 
condenser. 















10 



SECTION 30 
FUEL SYSTEM 
1 












SPECIFICATIONS: 

FUEL SYSTEM 

Type of Fuel Regular gasoline 

Filter In-line strainer 

Fuel Tank 1-1/4 U.S. Gallons 

AIR CLEANER 

Type AM 30900 Dry Filter 

Clean every 8 hours of service. 
Replace when dirty. 



ADJUSTING CARBURETOR: 

If the engine misses, backfires, surges 
or starts hard, carburetor adjustment 
may be required. 

Idle adjustment and high speed adjust- 
ment must be made at the same time as 
each affects the other. Adjust as fol- 
lows : 

1. Turn power adjusting screw clock- 
wise until closed. Close finger 
tight only. Then open one com- 
plete turn. 

2. Turn idle adjusting screw clock- 
wise until closed. Close finger 
tight only. Then open one and one- 
half turns . 



70 FS 1 



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Start engine and raise throttle 
lever on dash panel to "FAST" po- 
sition. Allow engine to warm up. 

Turn power or high-speed adjusting 
screw 1/8 turn each time, forward 
or backward, until engine runs 
smoothly at full throttle. Keep 
screw position slightly on the rich 
side (open) when operating tractor 
with power driven equipment such 
as the mower or snow thrower. 

Final idle adjustment should be 
made at an engine speed of 1200 to 
1700 rpm. Move throttle lever to 
lowered "slow" position and turn 
idle adjusting screw 1/8 turn each 
time, forward and backward, until 
engine idles smoothly. 



- 11 - 



SECTION 30 
FUEL SYSTEM 
2 



Raise throttle lever quickly to 
check for uniform acceleration. 
If engine misses , gas-air mixture 
is too lean. Turn power adjusting 
screw counterclockwise until posi- 
tive acceleration can be obtained. 
If excess exhaust smoke is noticed, 
mixture is too rich. Readjust idle 
screw, if necessary until good bal- 
ance is achieved and engine idles 
smoothly. Screw "A" adjusts the 
speed at which the engine idles. 
This is factory adjusted and will 
not normally require adjustment. 









********************* 



CARBURETOR SERVICE: 

For complete service on the inter- 
nal components of the carburetor 
as shown, refer to SM 2091, 2-7 HP 
Tecumseh Engine Service Manual. 



70 


FS 2 






I 





********************* 



FUEL TANK AND STRAINER: 

The fuel tank has an in-line 
strainer mounted at the fuel shut- 
off valve on the bottom of the tank. 

Clean strainer by washing in sol- 
vent. 

Compressed air may be used in the 
reverse direction of flow as shown. 
Be sure to use caution when using 
compressed air as damage could re- 
sult to the strainer. 



70 FS 3 




********************* 






- 12 - 



SECTION 40 
ELECTRICAL 
SYSTEM 1 



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SPECIFICATIONS: 

Battery, John Deere AM 30094 24 Amp. Hr. 12 volt 

System, Polarity Negative ground 

Starter Switch Ignition key & solenoid 

Alternate Starter Manual (Rope Pull) 

Ignition High tension flywheel magneto 

Spark Plug Gap 0.030 in. 

Breaker Point Gap 0.020 in. 

Generator Alternator w/rectifier 

Rectifier Fuse AGC6-6 Amp/-32V. 

Rectifier AM 30946 



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********************* 



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ELECTRICAL SYSTEM SERVICE: 

Probably one of the most confusing 
areas of the tractor to many service 
men is the electrical system. All of 
us at one time or another has had a 
customer tell us that his tractor 
"won't start". How are we going to find 
his problem and get the tractor running 
again? We could start replacing parts 
until finally we get the unit running, 
but this is not the approach of a good 
service man. In the following section 
of slides we will explain the compo- 
nents of the electrical system and how 
they function. They will be listed in 
sequence of how to test and find the 
defective part. 



70 ELECT 










Where Do We Begin? 

The customer said the tractor "won't 
start". We must first determine what 
exactly does he mean. We could gen- 
erally divide a complaint such as this 
one into two broad categories: 
One, the unit will not crank or 

startl 
Two, the unit will crank but not 

start! 



********************* 



13- 



SECTION 40 
ELECTRICAL 
SYSTEM 2 



CHARGE CIRCUIT: 

First we should begin by having a dia- 
gram of the tractors electrical system 
which will serve as a reference to all 
the components involved. 

Now let's proceed to find out why the 



Let's first say the unit will not crank 
or start. To do this we should check 
the obvious. 

1. Be sure the clutch pedal is 
fully engaging the safety 
start switch. 



70 ELECT 2 



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Be sure the PTO lever is out 
of gear. 



********************* 



We should use a jump wire from 
the battery positive post to the 
center lead on the solenoid. 
If the starter cranks, we should 
then check the neutral start 
switches, ignition switch and 
wiring harness with a continuity 
tester. SM 2059 shows all the 
details on how to check each of 
these electrical components. 



70 ELECT 3 






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********************* 



But what if it did not crank when we 
used the jump wire? We should then 
check the battery for loose or corroded 
connections. If this is O.K., then 
check the battery with a DC volt meter. 
To do this pull the spark plug wire off 
and crank the unit 15 seconds. If the 
battery reads less than 9.6 DC volts, 
the battery is bad. A fully charged 
battery range is 11.5 to 12.6 DC volts. 
If the battery reads above 9.6 DC volts, 
replace the solenoid. 



70 ELECT 4 







- 14 



SECTION 40 
ELECTRICAL 
SYSTEM 3 









While discussing battery testing we 
should talk about battery care. Always 
keep battery cables tight and free of 
corrosion. Use a baking soda solution 
or household ammonia cleanner to main- 
tain a clean battery and rinse with 
clear water. A battery will often 
consume small amounts of water. Water 
level should be maintained just below 
the split ring. Always keep the bat- 
tery charged to prevent freezing in 
cold weather. 



********************* 

70 ELECT 5 



If battery requires replacement be 
sure to connect the solenoid wire to 
positive (+) battery terminal and the 
ground wire to the negative (-) battery 
terminal as shown. Reversing these 
connections, even for a short time, may 
burn out fuse on the rectifier panel or 
cause other damage to the electrical 
system. Be sure the positive battery 
post and solenoid post is covered with 
a rubber boot. 





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********************* 



70 ELECT 6 






Should the owner desire to operate the 
tractor with the manual starter, when 
the battery is removed, disconnected 
or has a dead cell, always disconnect 
rectifier circuit at connector "A". 
Failure to do so will burn out the 
rectifier. 







********************* 



- 15 



SECTION 40 
ELECTRICAL 
SYSTEM 4 



70 ELECT 7 



Should the battery check out to be 
good, but only discharged it will be 
necessary to check the charge circuit 
further to determine the cause. 

The output amperage may be checked at 
the rectifier panel as shown here. 
Connect the positive lead of the amp 
meter to the output spade on the recti- 
fier panel. Connect the negative lead 
to the main wiring harness connector 
which connects to the output spade. 
Start engine and run at full RPM. 2-4 
Amps DC should be shown. 










A******************** 



70 ELECT 



If less than 2-4 Amps DC are shown or 
no Amp meter is available, check fuse 
and rectifiers with an Ohm meter. 
Full continuity should be shown in one 
direction only on rectifiers. Any 
reading other than this would indicate 
a defective rectifier. The fuse will 
show continuity in both directions. 




A******************** 



70 ELECT 9 



The rectifiers are protected by the 
fuse which will burn out if polarity 
is reversed at the battery connections. 
This can also result from incorrect 
booster battery connection. 

The tractor will start but the battery 
will not charge if the fuse is burned 
out. 




********************* 






- 16 



SECTION 40 
ELECTRICAL 
SYSTEM 5 






70 ELECT 6 






Operating the tractor with a burned 
out fuse can burn out the rectifier. 
If the fuse has burned out, disconnect 
rectifier circuit at connector "A" un- 
til a replacement fuse can be installed. 
Use an AGC6 - six amp fuse for replace- 
ment. 

Both rectifiers are identical and inter- 
changeable. However, they are direc- 
tional and must be inserted to fit the 
matching retainers. Align slotted end 
of rectifier with mating prongs in re- 
taining clip and press into place. Be 
sure tractor engine is stopped and ig- 
nition key is turned off before replac- 
ing rectifiers. 

Do not place retifier against contacts 
while in the reverse position. To do 
so may burn out rectifiers. 










********************* 



70 ELECT 10 



If the rectifier and fuse check O.K., 
the problem may lie in the stator 
assembly. The stator assembly has two 
charging coils. How do we check these 
charging coils? 




********************* 



70 ELECT 11 






Check the charging coils one at a time 
with a volt meter as shown. 16-24 AC 
volts should be read at each coil lead. 
Run the engine at full throttle or approxi 
mately 3600 RPM when making the test. 



******** 




SECTION 40 
ELECTRICAL 
SYSTEM 6 



70 ELECT 12 



Full continuity through both charging 
coils should be shown on an Ohm meter 
when installed in this manner. Lack 
of continuity would indicate a short 
or an open in the coils or leads . 




********************* 



70 ELECT 13 






The final check on the charge circuit 
would be to check the magnitism in the 
permanent magnets in the flywheel. 
These permanent magnets can be checked 
with a screwdriver as shown. The 
screwdriver will be attracted to the 
magnets if they are good. 




********************* 



70 GEN 2 



Let's suppose that rather than lack of 
charge at the battery we are overcharg- 
ing. Overcharging will be indicated 
by electrolyte fuming or "boiling out" 
of the battery. This will most often 
happen on a hot day after several hours 
of continued operation. To correct 
this situation disconnect rectifier 



circuit at connection 
tifier panel. 



on the rec- 



Other causes of battery spewage are 
the overfilling of the battery or the 
subjecting of the battery to excessive 
vibration. 




********************* 






- U 



SECTION 40 
ELECTRICAL 
SYSTEM 7 






IGNITION SYSTEM: 

Now let's suppose that the unit cranks 
but will not start. This poses an all 
together different problem. 

At this point we will assume that the 
fuel system is functioning properly. 
In a situation of cranking but not 
starting, carburetor, fuel tank, line 
and strain should all be checked as 
they may be malfunctioning. 



70 ELECT 14 







********************* 






The first check would be to remove the 
spark plug and crank the engine with 
the plug grounded as shown. If weak 
or no spark is produced, check the 
spark plug gap. Proper gap is .030. 
It may be necessary to install a new 
plug if the old plug is pitted or 
burned. Then retest by cranking en- 
gine. 



70 ELECT 15 










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********************* 



70 ELECT 16 



If still no spark is produced it will 
be necessary to remove the shrouding 
and flywheel to gain access to the ig- 
nition points. Use a puller as shown 
to remove flywheel. A rag placed be- 
tween the flywheel ring gear and bevel 
pinion on the starter will keep the 
flywheel from turning. 







********************* 



-19- 



Now turn the crankshaft until the lobe 
causes the points to open at the widest 
point. Check the points to see if they 
are pitted or burned. The proper point 
gap is .020. 

It is always a good policy to replace 
the condenser when the points are re- 
placed. A faulty condenser can ruin 
the points . 

Even though it was necessary to remove 
the top three head bolts to gain access 
to these electrical components it is 
not necessary to replace the head gas- 
ket. 



SECTION 40 
ELECTRICAL 
SYSTEM 8 



70 ELECT 17 










********************* 



70 ELECT 18 



If the ignition points appear to be 
good, than we should check the igni- 
tion coil. Remove the coil by prying 
off the wire retainer and disconnect- 
ing the leads . 




********************* 



70 ELECT 19 



These are five tests for an ignition 
coil: 

1. Coil power test. 

2. Coil high speed test. 

3. Coil surface insulation 
test. 

4. Continuity test. 

5. Coil ground test. 

Make all of these tests according to 
the instructions and specifications, 
which came with your tester. If no 
tester is available, install a new coil 
and check to see if this will correct 
the spark problem. 







********************* 

- 20- 



SECTION 40 
ELECTRICAL 
SYSTEM 9 






70 ELECT 20 



When replacing points or ignition coil 
do not remove or loosen the core and 
plate assembly as this will throw the 
engine out of time. 







********************* 









^ 



- 21 - 



SECTION 40 
ELECTRICAL 
SYSTEM 10 



ENGINE TIMING: 

When short blocking the engine or for 
any other service work which requires 
removal and replacement of the coil 
mounting core and plate assembly, it 
will be necessary to time the engine 
as follows : 

1. Remove grille and hood as- 
sembly, engine shrouding 
and flywheel. 

2. Remove cylinder head and 
gasket. 

3. Turn the crankshaft until 
the high point of the igni- 
tion cam causes the points 
to open. Set the point gap 
.020. 

4. Turn crankshaft until the 
piston reaches top-dead- 
center. Then turn the 
crankshaft counterclock- 
wise until the piston moves 
down .080/. 090 below top of 
cylinder block surface. 

5. Loosen the two screws that 
hold core and plate assembly 
to the cylinder. Remove the 
leads from point terminal 
when using Ohm meter or 
flashlight tester as shown. 
Position the core and plate 
assembly so that ignition 
cam on crankshaft just be- 
gins to open breaker points. 
This breaks the continuity 
and will be shown on the 
tester. Tighten core and 
plate assembly mounting 
screws to retain adjustment. 

6. Reassemble engine. Be sure 
to install new cylinder head 
gasket when reassembling. 
Tighten head bolts to 140- 
200 in. lbs. 



70 ELECT 21 
















********************* 






22- 









STARTER: 

The 70 Tractor is equipped with a 
starter motor. When the ignition 
switch is in the start position the 
starting circuit is closed and the 
armature starts to rotate. The ben- 
dix drive pinion moves out on a 
splined sleeve into mesh with the fly- 
wheel ring gear. The pinion than ro- 
tates along with the armature shaft 
to crank the engine. When the engine 
starts, the flywheel begins to turn 
faster than the armature in the starter, 
which throws the pinion back into the 
disengaged position. Then the igni- 
tion is put in the run position, the 
starting circuit is opened and the 
armature coasts to a stop. A small 
spring holds the pinion in the re- 
tracted position. 



SECTION 40 
ELECTRICAL 
SYSTEM 11 



70 ELECT 22 





















CAPASSSMMY-- 














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Cranking should be held to a maximum 
of 60 seconds to avoid overheating. 



******************** 



70 ELECT 23 






To check the fields for a ground, 
place one test lead on the starter 
terminal (Brush) and the other test 
lead to the starter housing. If con- 
tinuity exists, fields are grounded 
and housing must be replaced. 




********************* 



70 ELECT 24 



To check end cap for ground, place one 
test lead on end cap and other test 
lead on the brush that connects to 
fields. If this test shows continuity, 
end cap is shorted and needs to be re- 
placed. 



*************** 

- 23- 




SECTION 40 
ELECTRICAL 
SYSTEM 12 



70 ELECT 25 



To check commutator of the armature 
for ground, place one test lead on the 
armature shaft and pass the other test 
lead around on the commutator. If con- 
tinuity exists at any section turn down 
commutator or replace armature. 




********************* 

70 ELECT 22 



__ 



Brushes should be replaced when they 
are worn down to one-half their ori- 
ginal length or any time the starter 
is being reconditioned. Clean com- 
mutator with 00 sandpaper whenever 
brushes are replaced. 
Assembly tips: 

1. Apply a light film of SAE 
#10 oil to armature shaft 
splines and bearings in 
the end cap . 

2. Use spacing washers as re- 
quired to obtain .005 to 
.015 inch armature end 
play. After assembly, 
check for freeness. Add 
or remove spacing washers 
as necessary. 

3. Install end cap by inserting 
a snap ring pliers or a 
needle-nose pliers and 
spreading brushes enough 

to slip brushes over commu- 
tator. The starter body 
has a mark and an indenta- 
tion on the inside which 
must fit into the two in- 
dentures on the cap. 

4. Torque lock not on armature 
shaft 130-150 inch lbs. 

5. Torque thru bolts 40-55 
inch lbs. 

























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********************* 






24 



r- 






SPECIFICATIONS: 

BRAKES 

Type Friction, pedal operated 

Parking.... Hand lock to foot brake 

CLUTCH V-belt 

TRANSMISSION 

Type Transaxle 

Gear Selections/3- forward, 1 reverse 

TRAVEL SPEEDS (mph) 

1st. Gear 1.9 

2nd. Gear 3.3 

3rd. Gear 5.0 

Reverse 2.6 

Transmission Capacity. 3 U.S. Pints 
Type of Lubricant AM 30200M 



SECTION 50 
POWER TRAIN 
1 



********************* 



S~~ 



<~- 



REPLACING PRIMARY BELT: 

CAUTION: Remove. ignition kzy and 
i>pank plug wiAe. fifiom tttacXofi bzfioie. 

Remove locking pin and disconnect 
clutch arm from fulcrum and clutch 
cone. Push up on front idler and slip 
primary belt off rear sheave first. 
Then, remove belt from engine sheave. 

Place a new primary belt on sheaves 
with bottom strand running from rear 
sheave to left-hand side of front sheave, 
Reassemble clutch arm and locking pin. 

NOTE: Installing bzlt wi£h a fizv&uz 
twiAt mill nej>ul£ in fizvuue. tuacton. 
tnxwzl and podhlbln tfuxmaxlo. damage.. 



70 PT 1 




***************** 



* * * * 



25 - 



REPLACING SECONDARY BELT: 

Depress clutch-brake pedal and set 
parking brake. Remove four cap screws 
(one under each fender and two under 
seat) holding fender-deck in place. 

With fender-deck removed, loosen cap 
screws and slide rear belt guide out 
of the way. Remove front belt guide. 
Unhook spring from front idler arm. 
Remove primary belt from rear sheave. 

Remove spring hooked to rear idler arm. 
Loosen cap screws on rear idler mount. 
Remove secondary belt. 

Install new secondary belt on sheaves. 
Tighten cap screws on rear idler mount. 
Replace primary belt and hook spring to 
front idler arm. Install front belt 
guide. Hook spring to rear idler arm. 

Repostion rear belt guide and tighten 
cap screws. Replace fender-deck and 
tighten cap screws. 

IMPORTANT: Notice the position of the 
belt guide on the rear idler. The 
function of the guide is to crimp the 
belt when the clutch pedal is depressed 
and stop the belt rotation. Also note 
the adjustment on the rear belt guide. 
This guide also functions to get the 
secondary belt to stop turning when the 
clutch pedal is depressed. If these 
two guides are not adjusted properly, 
the secondary belt will creep and the 
transmission gears will clash when 
trying to shift. Damage will result 
to transmission. 



SECTION 50 
POWER TRAIN 
2 



70 PT 2 








REAR SECONDARY 


j 




~*^L'"" / REAR 
S^B5l_ S .IDLER 




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•■ 



















********************* 






26 - 









TRANSAXLE REMOVAL AND REPLACEMENT: 

Remove fender-deck assembly as for sec- 
ondary belt replacement. Remove secon- 
dary belt idler spring. Loosen rear 
belt guide. 

Remove cotter key in brake strap. Re- 
move belt from transaxle input sheave 
only. Jack up tractor in front of 
transaxle as shown. Remove four bolts 
on top of transaxle. Raise jack and 
roll transmission and wheel assembly 
out from under frame. 



SECTION 50 
POWER TRAIN 
3 



70 PT 3 




****************** 



* * 



70 PT 4 






Remove snap rings on end of axles to 
remove wheels. 

Remove input sheave and brake sheave 
and assembly. 




********************* 



70 PT 5 



^ 



The transaxle is now ready for internal 
service. 

Refer to SM 2059 for three-speed trans- 
axle service. 

While this is in the service manual for 
110 and 112 Tractors, ( -100,000) 

the disassembly and reassembly of the 
three-speed transaxle will apply to the 
transaxle in the 60 and 70 Tractors. 




******************* 
Reverse procedure for installation. 



* * 



MOTE: Be 6lui& bhake ithjxp qoqj> oveA. 
top oh welded guide, on lefit-hand hi.de. 



27 



SECTION 70 
MISCELLANEOUS 
1 



STEERING GEAR ADJUSTMENT: 

To remove excessive backlash (loose 
steering) and to properly adjust 
steering gear, follow this procedure: 

1. Disconnect ball joint from 
lever arm. 

2. Loosen jam nut and stud two 
or three turns. 

3. Remove cotter pin holding 
adjusting plug in gear 
housing. Use screwdriver 
to turn adjusting plug into 
column until tight. Back 
plug out until steering 
wheel turns freely with no 
drag. Lift up on steering 
wheel to check end play. 



70 MISC 1 



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steering! 






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********************* 



70 MISC 2 



Turn plug only far enough 
after adjusting to insert 
cotter pin through housing 
and closest slot in plug. 
Bend one prong of cotter pin 
out to retain plug. 
Loosen jam nut on pivot bolt 
and tighten only the inside 
nut using a thin open end 
wrench until all end play 
(see arrow) is removed or 
until the distance between 
1/16 and 3/32-inch. Tighten 
jam nut. Check this by hand. 
(15/16" wrench JDST4 is avail- 
able from Service Tools, Inc., 
1900 Indiana Ave., Chicago, 
111. , 60616) 




********************* 






-28 - 









Find the center of the 
steering range by turning 
the steering arm until a 
line between the centers 
of the pivot bolt and 
joint is vertical. 



SECTION 70 
MISCELLANEOUS 
2 



70 MISC 3 




********************* 






70 MISC 1 



Turn stud in (clockwise) 
until snug to remove all 
backlash. Then move 
steering arm through its 
full range in both directions 
(front to rear). Steering 
wheel will turn as this 
check is made. When pro- 
perly adjusted, a slight 
drag can be detected in 
the midpoint of the range 
(when line between the 
pivot bolt and ball joint 
is vertical). Tighten 
jam nut to 40 ft. lbs. 
torque. 







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Make final test by turning 
steering arm through full 
range . 

Connect ball jount to 
lever arm. 



* * * 



***************** 



- 29 - 



STEERING COLUMN REMOVAL SEQUENCE: 

Remove battery and battery base. 

Disconnect clutch throw-out link at 
throw-out arm, main wiring harness at 
ignition switch and neutral start 
switch. 

Remove steering wheel and pedestal. 



SECTION 70 
MISCELLANEOUS 
3 



70 MISC 4 







********************* 



70 MISC 5 



Disconnect drag link and remove bolts 
fastening lower end of steering column 
to tractor base. 

Use Loctite on bolt threads that secure 
steering column to tractor base and re- 
verse removal procedure when installing 
steering column back in tractor. 




********************* 



70 MISC 6 



PTO CLUTCH: 

Repacking clutch bearings. 

Remove locking pin and detach linkage 
from PTO clutch assembly. 

Remove old grease from bearings in 
lower clutch cone with solvent at the 
beginning of each spring and fall sea- 
son or sooner if dirt is found in the 
bearings. Dry thoroughly and repack 
bearings with John Deere High- 
Temperature Grease, AT 17659 T, avail- 
able in one-pound cans. 



Replace linkage and locking pin. 

********************* 







-30 



SECTION 70 
MISCELLANEOUS 
4 



^ 






Adjusting power take-off clutch. 

Check clutch adjustment to be certain 
clutch is not slipping and power driven 
equipment is clutching and declutching 
properly. To check adjustment: 

1. Engage PTO clutch. 

2. Observe that clutch arm is 
level or parallel with tractor 
frame. If not, remove locking 
pin and lower clutch arm. Loos- 
en jam nut and turn fulcrum 
either up or down until arm 

is approximately level when 
PTO clutch is engaged and 
locking pin is in place. 



70 MISC 7 
















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********************* 









Engage and disengage the 
clutch slowly with the PTO 
lever. Observe at what point 
the clutch cones begin to con- 
tact each other. From this 
point to full engagement of 
the PTO lever, the clutch rod 
should deflect 1/2-inch. This 
will properly tension clutch 
cones for positive engagement. 
Move nuts on end of clutch rod 
as required until proper deflec- 
tion is obtained. 




********************* 






-31 



SECTION 70 
MISCELLANEOUS 
5 



Adjusting power take-off clutch brake. 

The PTO clutch brake stops the mower 
blades or snow thrower rotor quickly 
after disengaging the drive with the 
PTO lever. 

Engage the PTO lever and check the dis- 
tance between the brake and clutch 
cone. When properly adjusted, this 
distance should be approximately 1/16- 
inch. 



70 


MISC 


9 














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CLUTCH BRAKE 











A******************** 



70 MISC 10 



If adjustment is required, loosen cap 
screw and slide brake shoe in slotted 
hole until 1/16-inch clearance is ob- 
tained. Tighten cap screw firmly. 







********************* 






_ 



32- 



SECTION 80 
ATTACHMENTS 
1 






34 ROTARY MOWER: 

The 34 Rotary Mower will fit either 
the 60 or 70 Lawn Tractor. The mower 
will be shipped with the 70 Tractor. 

Complete installation and leveling 
instructions are given in the Operator's 
Manual. The importance of leveling the 
mower cannot be over emphasized. Always 
level the mower at the beginning of each 
mowing season or whenever the mower has 
been removed and reinstalled on the trac- 
tor. 

To level the mower: 

1. Park tractor on a hard flat 
surface such as a driveway, 
sidewalk or garage floor. 

2. Inflate rear tires to exactly 
6 psi and front tires to 12 
psi. Check inflation with a 
low pressure tire gauge. 

3. Check to be sure mower gauge 
wheels are both in the same 
adjusting hole. They can be 
in any one of the four holes, 
but they must both be in iden- 
tical positions. 

4. Raise mower with lift lever 
until gauge wheels are off the 
ground. 

5. Measure distance between the 
ground and the bottom of the 
mower deck on each end of the 
mowe r . 



34 RM 1 




******* 



************* 









When properly leveled the dis- 
tance will be equal on each end 
of the mower. 

If adjustment is required, re- 
move adjustable clevis from 
rear draft link and turn clevis 
either up or down until right- 
hand dimension is exactly the 
same as left-hand dimension. 

Tighten jam nut firmly against 
clevis after adjusting. 
Adjust cutting height with lift 
lever and stop as instructed in 
the Operator's Manual. 



34 RM 2 




- 33- 
***************** 



* * * * 



SECTION 80 
ATTACHMENTS 
2 



34 RM 3 



The 34 Rotary draft arms are non- 
adjustable. The mower is designed to 
hang on the tractor in such a position 
to allow the blade to cut lower in the 
front than in the rear. 

Should some adjustment be required, 
loosen the bolts holding the draft 
frame and push down and back to lower 
the front of the mower. 

The 70 Tractor has new front wheel 
spindles (AM 32642 R.H. and AM 32643 L.H.) 
which will also fit 60 Tractors ( 

20001) . These spindles will lower the 
front of the tractor about 1/2-inch. 







********************* 



Other attachments for the 70 Tractor 
are the same as those for the 60. The 
40 Front Blade and 32 Snow Thrower 
assembly and installation instructions 
are explained quite well in the Opera- 
tor's Manual. 












34 -